This invention relates to a cryogenic wound rotor designed for lightweight, high-voltage generators.
Aerospace power requirements dictate direct generation of high voltage alternating current at high power levels in lightweight rotating machines. Some prior work toward providing such a generator has used superconductor-wound rotors operating at a liquid helium temperature.
U.S. Patents of interest include U.S. Pat. No. 3,720,777 to Sampson et al, U.S. Pat. No. 3,748,615 to Bogner et al, U.S. Pat. No. 3,778,895 to Nomura et al, U.S. Pat. No. 3,890,701 to Diepers, U.S. Pat. No. 4,384,168 to Kenney, and U.S. Pat. No. 4,529,955 to Schuster et al.
Kenney discloses a conductor for a fluid-cooled winding. While the patent is concerned primarily with superconductors it mentions conductors formed solely of normally conducting materials, such as copper, aluminum, etc., which are used in fluid-cooled motors, generators, transformers and the like. In FIG. 4 the Kenney patent shows substantially rectangular cross section conductors 5 spaced by flow channels, and strips of insulation 9 wound between turns. Nomura et al show in graph form the resistivity of substantially pure aluminum at liquid helium and liquid hydrogen temperatures. Diepers suggests a composite conductor having an aluminum core. Sampson et al show in FIG. 5 a low loss transmission line comprising parallel flat ribbons spaced by insulation 35. Cooling is illustrated in FIG. 4 of this patent. Cooling channels in a superconducting magnet coil are illustrated at 4 in Bogner et al. In Schuster et al cooling is applied to magnetic coils wherein the material of the turns is not specified and presumably not necessarily superconducting.